Thread spool stand device and sewing machine provided with thread spool stand device

ABSTRACT

A thread spool stand device is disclosed. The thread spool stand device includes a thread spool base and a thread spool pin that has a base end thereof secured to the thread spool base and that allows attachment of a thread spool. The thread spool stand device further includes a positioning mechanism that determines position of attachment of the thread spool relative to the thread spool pin. The positioning mechanism includes a contact section that contacts an inner peripheral surface of a core of the thread spool. The contact section is radially movable responsive to variation in an inner diameter of the core such that the contact section expands radially outward or contracts radially inward to be equally spaced from an axial center of the thread spool pin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application 2010-158689, filed on Jul. 13,2010, the entire contents of which are incorporated herein by reference.

FIELD

The present disclosure relates to a thread spool stand device providedwith spool pins for attachment of thread spools. The present disclosurefurther relates to a sewing machine provided with such thread spoolstand device.

BACKGROUND

Sewing machines are known that are provided with a thread spool standhaving a plurality of thread spool pins. The thread spool pins are madeof thin bars that extend upward. A thread spool is made of a generallycylindrical core which may or may not be tapered that has thread woundon it. Thus, the thread spool exhibits a tapered or a cylindricalprofile. The cylindrical core is hollow and has a vertically penetratingcentral through hole. The thread spool is attached to the thread spoolstand device so as to pass the thread spool pin through the centralthrough hole of the core. The thread drawn from the thread spoolattached to the threads spool pin is guided by a thread guide mechanismlocated above the thread spool and is ultimately supplied to the sewingneedle by way of components such as a thread tension regulator andthread take-up. In order to keep the tension of thread drawn from thethread spool constant or in order to prevent physical contact betweenthe neighboring thread spools, the thread spool is preferably locatedsuch that axial center of the thread spool and the axial center of thethread spool pin are coincident when the thread spool is attached to thethread spool stand device.

Given such background, a configuration for attaching a thread spool isknown that has a plurality of leaf springs provided on the outerperiphery of the thread spool pin such that the elasticity of the leafsprings are exerted on the inner peripheral surface of the typicallycylindrical core of the thread spool. Further, an umbrella memberconfigured by a plurality of elastically deformable vanes is providedaround the outer periphery of the thread spool pin. The above describedconfiguration may provide one solution for locating the thread spoolsubstantially at axial center of the thread spool pin.

However, the above described configuration of imparting the elasticityof the leaf springs and the vanes disposed circumferentially on theinner peripheral surface of the cylindrical core may fail to produceequal distributions of elasticity due to unequal amount of elasticdeformation of the circumferentially disposed leaf springs and vaneswhich typically originates from dimension variation of the parts used.Failure to obtain equalized elastic deformation of the leaf springs andvanes may cause the axial center of the thread spool to be displacedfrom the axial center of the thread spool pin. Further, because leafsprings and vanes only provide small range of elastic deformation, notenough elasticity is produced when handling sizeable thread spools thathave larger cylindrical cores with larger inner diameters. Such sizefactors may also cause displacement problems as well.

As described above, the conventional configuration also lacks in thecapacity to accommodate thread spools ranging in size and dimensions ofthe inner diameters of cores.

SUMMARY

One object of the present disclosure is to provide a thread spool standdevice that allows attachment of a thread spool such that the axialcenter of the thread spool is coincident with the axial center of athread spool pin and that is capable of accommodating thread spools ofvarious sizes. Another object of the present disclosure is to provide asewing machine provided with such thread spool stand device.

In aspect, a thread spool stand device is disclosed. The thread spoolstand device includes a thread spool base and a thread spool pin thathas a base end thereof secured to the thread spool base and that allowsattachment of a thread spool. The thread spool stand device alsoincludes a positioning mechanism that determines position of attachmentof the thread spool relative to the thread spool pin. The positioningmechanism includes a contact section that contacts an inner peripheralsurface of a core of the thread spool. The contact section is radiallymovable responsive to variation in an inner diameter of the core suchthat the contact section expands radially outward or contracts radiallyinward to be equally spaced from an axial center of the thread spoolpin.

Other objects, features and advantages of the present disclosure willbecome clear upon reviewing the following description of theillustrative aspects with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view generally depicting a sewing machineaccording to a first exemplary embodiment of the present disclosure;

FIG. 2 is a partial perspective view of a thread spool stand device;

FIGS. 3A to 3D are plan, front, side, and bottom views of a thread spoolpin and a positioning mechanism;

FIGS. 4A to 4E are plan, front, side, and bottom views of a link base;

FIGS. 5A to 5E are plan, front, side, and bottom views of an upper linkelement;

FIGS. 6A to 6E are plan, front, side, and bottom views of a lower linkelement;

FIGS. 7A to 7E are plan, front, side, and bottom views of a slider;

FIGS. 8A and 8B are front and side views of a link shaft;

FIGS. 9A to 9C illustrate how a thread spool is attached to the threadspool pin;

FIGS. 10A to 10C correspond to FIGS. 9A to 9C;

FIGS. 11A and 11B are front views of the thread spool pin and thepositioning mechanism according to a second exemplary embodiment of thepresent disclosure; and

FIG. 12 is a front view of the thread spool stand device according to amodified exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

A first exemplary embodiment of the present disclosure will be describedwith reference to FIGS. 1 to 10 through application to a multi-needleembroidery sewing machine hereinafter represented as multi-needle sewingmachine M. It is to be noted that as viewed in FIG. 1, the direction inwhich the user positions him/herself relative to multi-needle sewingmachine M is the forward direction and the opposing direction,naturally, is the rear direction.

Referring to FIG. 1, multi-needle sewing machine M is primarilyconfigured by a pair of left and right feet 1, pillar 2, arm 3, cylinderbed 4, and needle-bar case 5. Pillar 2 stands substantially upright fromthe rear end of feet 1. From the upper portion of pillar 2, arm 3extends forward so as to oppose cylinder bed 4 extending forward fromthe lower end of pillar 2. Needle-bar case 5 is attached on the frontface of arm 3. Feet 1, pillar 2, arm 3, and cylinder bed 4 arestructurally integral and are collectively represented as sewing machinebody 6. Sewing machine body 6 is typically provided with components suchas a controller not shown that is responsible for controllingmulti-needle sewing machine M and control panel 7.

On the front face of control panel 7, a vertically long liquid crystaldisplay (LCD) 7 a and various switches such as start/stop switch 7 b areprovided for user operation. On the sidewall of control panel 7,interfaces such as slot 7 c is provided to allow insertion of computerreadable medium not shown that is capable of storing information such asembroidery data pertaining to various types of embroidery patterns. Onthe front face of LCD 7 a, touch panel 7 d including a plurality oftouch keys configured by transparent electrodes are provided on the forallowing user operation to execute various functionalities and to makevarious specifications for parameter settings and thread spoolreplacement setting, etc.

On the upper surface of cylinder bed 4, needle plate 8 is provided thathas needle hole 8 a that is representative of a needle drop position ofa sewing needle not shown. Above feet 1, carriage 9 oriented in the leftand right direction is disposed which contains an X-drive mechanism notshown that drives a frame mount base not shown provided in front ofcarriage 9 in the X direction or the left and right direction. Withinthe left and right feet 1, a Y-direction drive mechanism not shown isprovided that drives carriage 9 in the Y direction or the front and reardirection. X-direction drive mechanism is driven by an X-axis motor notshown whereas the Y-direction drive mechanism is driven by a Y-axismotor not shown. The workpiece cloth not shown to be embroidered is heldby a rectangular embroidery frame not shown which is mounted on theframe mount base. The embroidery frame is driven in the X directionalong with the frame mount base by the X-direction drive mechanism, andin the Y direction in synchronism with carriage 9 by the Y-directiondrive mechanism. The workpiece cloth is thus, fed in the left and rightdirection as well as the front and rear direction.

The above described needle-bar case 5 supports ten vertically extendingneedle bars not shown that are arranged side by side in the left andright direction. Needle bars are allowed to move up and down and eachneedle bar has a sewing needle not shown attached to its lower end.Needle-bar case 5 is further provided with ten thread take-ups 10 a to10 j that are associated with the ten needle bars. Thread take-ups 10 ato 10 j are also allowed to move up and down and are aligned side byside in the left and right direction. Needle-bar case 5 has a forwardlydeclining thread tension regulator base 11 on its upper side that mergesin continuation with the upper end of needle bar case 5. Thread tensionregulator base 11 is provided with ten thread tension regulators 12 a to12 j for making adjustments in thread tension. Thread tension regulatorbase 11 is further provided, at its rear end, ten laterally alignedthread inlets 13 a to 13 j.

At the front end of arm 3, laterally extending guide rail 3 a isprovided to provide support to needle-bar case 5 as well as allowingneedle-bar case 5 to slide laterally along it. Arm 3 contains aneedle-bar case transfer mechanism not shown that transfers needle-barcase 5 in the left and right direction. The needle-bar case transfermechanism, driven by a drive motor not shown, switches a single pair ofneedle bar and thread take-up selected from the ten pairs of needle barsand thread take-ups 10 a to 10 j to the needle drop position. The pairof needle bar and thread take-up (one of 10 a to 10 j) switched to theneedle drop position is driven up and down in synchronism with a sewingmachine motor not shown provided at pillar 2. The pair of needle bar andthread take-up work in coordination with a rotary hook not shownprovided at the front edge of cylinder bed 4 to form embroidery stitcheson the workpiece cloth held by the embroidery frame.

At the upper portion of sewing machine body 6, thread spool stand device14 is provided which includes support base 15, thread spool bases 16 and17, threading mechanism 18, and thread guide mechanism 19. Support base15 is provided on the upper surface of arm 3. Thread spool bases 16 and17 each carry five thread spools. Threading mechanism 18 is responsiblefor threading the threads drawn from the thread spools. Thread guidemechanism 19 guides the threads threaded to threading mechanism 18.

Threading mechanism 18 is located above thread spool bases 16 and 17 andis provided with a laterally extending threading member 20. Threadingmember 20 is located directly above a total of ten thread spool pinslater described in detail distributed to thread spool bases 16 and 17.On the front side panel of threading member 20, ten threading holes 21 ato 21 j are defined, whereas on the rear side panel, six threading holes22 a to 22 f are defined to allow passage of threads.

Thread guide mechanism 19 is provided with a laterally extending threadguide member 23. Thread guide member 23 is provided with ten laterallyspaced thread-guide insert holes 24 a to 24 j. Between thread guidemember 23 and the aforementioned thread inlets 13 a to 13 j, a laterallyextending mid thread-guide member 25 is provided which is provided withten laterally spaced mid thread-guide insert holes 26 a to 26 j.Thread-guide insert holes 24 a to 24 j and mid thread-guide insert holes26 a to 26 j are laterally spaced by equal spacing.

Thread guide member 23, mid thread-guide member 25 and the rear endportion of thread tension regulator base 11 are joined by midthread-guide link mechanism 27. Mid thread-guide link mechanism 27includes a pair of first link members 28 and 29 and a pair of secondlink members 30 and 31. First link members 28 and 29 are responsible forjoining thread guide member 23 and mid thread-guide member 25. Secondlink members 30 and 31 are responsible for joining mid thread-guidemember 25 and the rear end portion of thread tension regulator base 11.First link member 28 and second link member 30 are pivotably supportedby one another. Similarly, first link member 29 and second link member31 are pivotably supported by one another. Thus, when needle-bar case 5is moved from side to side by the needle-bar transfer mechanism, midthread-guide member 25 follows the side to side movement through thelinkage provided by mid thread-guide link mechanism 27.

The threads drawn from the thread spools are ultimately passed throughthread inlets 13 a to 13 j by way of: threading holes 21 a to 21 j and22 a to 22 j of threading member 20, thread-guide insert holes 24 a to24 j of thread guide member 23, and mid thread-guide insert holes 26 ato 26 j of mid thread-guide member 25. The threads passed through threadinlets 13 a to 13 j are further passed through components such as theaforementioned thread tension regulators 12 a to 12 j and threadtake-ups 10 a to 10 j to ultimately thread the eye of each sewingneedle. The strings of threads maintain a parallel relationship with oneanother as they pass through thread-guide insert holes 24 a to 24 j ofthread guide member 23, mid thread-guide insert holes 26 a to 26 j ofmid thread-guide member 25, and thread inlets 13 a to 13 j. Because midthread-guide member 25 follows the side to side movement of needle-barcase 5 actuated by the needle-bar case transfer mechanism by way of theaforementioned link mechanism 27, thread tangling can be preventedeffectively.

Next, a description will be given on thread spool bases 16 and 17.Thread spool bases 16 and 17 are each supported by support base 15provided at the upper rear portion of arm 3. Thread spool bases 16 and17 are disposed symmetrically relative to arm 3 in front view. Becausethread spool bases 16 and 17 are identical in structure, descriptionwill be given hereinafter based on thread spool base 16 with referenceto FIG. 2.

Referring to FIG. 2, thread spool base 16 is provided with base 32 whichis trapezoidal in plan view. On upper surface 32 a of base 32, fivedisc-shaped mount stages 33 to 37 are provided which are structurallyintegral with upper surface 32 a. Each of mount stages 33 to 37 areprovided with LED (Light Emitting Diode) not shown that indicate thecolor of the thread spool. The color indicated by the LED can be seenthrough windows 33 a to 37 a. Five thread spool pins 43 to 47, one foreach of mount stages 33 to 37, extend upward from the upper surfacecenters of mount stages 33 to 37. On the upper surface of each of mountstages 33 to 37, disc-shaped sponges 38 to 42 are provided that have athough hole defined on it to allow insertion of thread spool pins 43 to47. Sponges 38 to 42 are provided to prevent the thread drawn from thethread spool from being stuck underneath the thread spools.

Each of mount stages 33 to 37 has a through hole not shown defined ontheir diametric centers through which base ends 43 a to 47 a of threadspool pins 43 to 47 are inserted whereby thread spool pins 43 to 47 aresecured on mount stages 33 to 37. The axial centers of thread spool pins43 to 47, the diametric centers of mount stages 33 to 37, and thediametric centers of sponges 38 to 42 are coincidental. Further, tips 43b to 47 b of thread spool pins 43 to 47, distal from base ends 43 a to47 a, are tapered to facilitate insertion of the thread spools.

The five thread spool pins 43 to 47 are positioned such that two arelaterally aligned in the front row and three are laterally aligned inthe back row. In the first exemplary embodiment, thread spool pins 44and 46 are aligned in the front row whereas thread spool pins 43, 45 and47 are aligned in the back row. Each of thread spool pins 43 to 47 areprovided with either of positioning mechanisms 48 to 52. Positioningmechanisms 48 to 52 are mechanically attached to thread spool pins 43and 47 and are all identical in structure. In the following description,positioning mechanism 48 attached to thread spool pin 43 will beexplained in detail with reference to FIGS. 3A to 8B to describepositioning mechanisms 48 to 52 in general.

As shown in FIGS. 3A to 3D, positioning mechanism 48 is provided withlink mechanism 53 and compression spring 54. Compression spring 54 iswound around thread spool pin 43 and is compressed and decompressed aswill be later described. On a portion of thread spool pin 43 locatedabove compression spring 54, link mechanism 53 is provided. The upperend of compression spring 54 and the lower end of link mechanism 53,which corresponds to the bottom surface of a later described slider, areplaced in contact. Link mechanism 53 includes link base 55, threeconnection links 56, and slider 57.

Referring to FIGS. 4A to 4E, link base 55 is primarily configured bylink base body 58 which is provided with insert hole 59 a, three upperlink element supports 59 b, three notches 59 c, and six link shaft holes59 d. Insert hole 59 a allows insertion of thread spool pin 43. Thethree upper link element supports 59 b configured as bifurcatedprotrusions are angularly displaced by 120 degrees. The three notches 59c defining the bifurcations extend radially inward toward the diametriccenter and are also angularly displaced by 120 degrees. The six linkshaft holes 59 d horizontally penetrate upper link element supports 59b.

Each of the three connection links 56 are provided with upper linkelement 60 and lower link element 61. As can be seen in FIGS. 5A to 5E,upper link element 60 is primarily configured by upper link body 62having base end 62 a and extreme end 62 b. At base end 62 a side,thinned tip 63 a and link shaft hole 63 b are provided, whereas atextreme end 62 b side, notch 63 c extending axially toward base end 62 aand link shaft hole 63 d are provided. Referring now to FIGS. 6A to 6E,lower link element 61 is primarily configured by lower link body 64having base end 64 a and extreme end 64 b. At base end 64 a side, linkshaft hole 65 a is provided, whereas at extreme end 64 b side, linkshaft hole 65 b is provided.

Referring now to FIGS. 7A to 7E, slider 57 is primarily configured byslider body 66 provided with insert hole 67 a, three lower link supports67 b, three notches 67 c, and six link shaft holes 67 d. Insert hole 67a allows insertion of thread spool pin 43. The three lower link elementsupports 67 b configured as bifurcated protrusions are angularlydisplaced by 120 degrees. The three notches 67 c defining thebifurcations extend radially inward toward the diametric center and arealso angularly displaced by 120 degrees. The six link shaft holes 67 dhorizontally penetrate lower link element supports 67 b. As can be seenin FIGS. 8A and 8B, link shaft 68 is formed as a pin.

Link base 55 and each of upper link elements 60 are assembled by:inserting thinned tip 63 a at base end 62 a side of upper link element60 into notch 59 c, and inserting link shaft 68 across link shaft hole59 d of link base 55 and link shaft hole 63 b on base end 62 a side ofupper link element 60. Tight fitting is established between link shafthole 59 d and link shaft 68 and thus, link shaft 68 will not fall outafter assembly. In contrast, loose fitting is established between linkshaft hole 63 b and link shaft 68 to allow each of upper link elements60 to be rotatable relative to link base 55.

Each of upper link elements 60 and each of lower link elements 61 areassembled by: inserting extreme end 64 b side of lower link element 61into notch 63 c of extreme end 62 b side of upper link element 60, andinserting link shaft 68 across link shaft hole 63 d on extreme end 62 bside of upper link element 60 and link shaft hole 65 b on extreme end 64b side of lower link element 61. Tight fitting is established betweenlink shaft hole 63 d and link shaft 68 and thus, link shaft 68 will notfall out after assembly. In contrast, loose fitting is establishedbetween link shaft hole 65 b and link shaft 68 to allow each of upperlink elements 60 and lower link elements 61 to be rotatable relative tothe other.

Each of lower link elements 61 and slider 57 are assembled by: insertingbase end 64 a side of lower link element 61 into notch 67 c of slider57, and inserting link shaft 68 across link shaft hole 67 d of slider 57and link shaft hole 65 a on base end 64 a side of lower link element 61.Tight fitting is established between link shaft hole 67 d and link shaft68 and thus, link shaft 68 will not fall out after assembly. Incontrast, loose fitting is established between link shaft hole 65 a andlink shaft 68 to allow each of lower link elements 61 to be rotatablerelative to slider 57.

Link mechanism 53, as described above, is configured by an assembly oflink base 55, slider 57, three upper link elements 60, three lower linkelements 61, and nine link shafts 68. Link mechanism 53 is mounted onthread spool pin 43 such that thread spool pin 43 is inserted throughinsertion hole 59 a of link base 55 and insertion hole 67 a of slider57. The outside portion of extreme end 62 b of upper link element 60,which is most distant from the axial center of thread spool pin 43, isidentified as contact section 69.

The inner diameter of insert hole 59 a of link base 55 is configured tobe slightly smaller than the outer diameter of thread spool pin 43.Thus, frictional force is exerted between the inner peripheral surfaceof insert hole 59 a and the outer peripheral surface of thread spool pin43 to secure thread spool pin 43 to link base 55 located at the upperportion of link mechanism 53. Link base 55 thus, stays unmoved duringthe attachment of the thread spool. However, by applying force that isgreater than the frictional force, the user is allowed to move thepositioning of link base 55. The inner diameter of insert hole 67 a ofslider 57, on the other hand, is configured to be greater than the outerdiameter of thread spool pin 43. Thus, slider 57 located at the lowerportion of link mechanism 53 is allowed to slide smoothly along threadspool pin 43. Slider 57 is disposed above compression spring 54. Thethree upper link elements 60, the three lower link elements 61, slider57, and the six link shafts 68 each rests at a position where linkratio, relative positioning, joint friction, and weight are balanced. Inthis state, compression spring 54 is slightly compressed, meaning thatthe underside of slider 57 is placed in consistent contact with theupper end of compression spring 54. The slight compression, which may bereferred to as the initial state, is maintained while the thread spoolis not attached. As described above, slider 57 is supported bycompression spring 54 and upper and lower link elements 60 and 61conjunctively define a bend which defines a predetermined angle.

The elasticity exerted by the compression of compression spring 54biases slider 57 upward through the contact established betweencompression spring 54 and slider 57. The bias exerted on slider 57 actsupon each of contact sections 69 to spread them radially by way of thethree lower link elements 61.

Next, a description will be given on the working of the above describedconfiguration.

FIGS. 9A to 9C illustrate how thread spool 71 is attached to threadspool pin 43. In the shown example, core 72 of thread spool 71 beingattached has a relatively sizeable inner diameter. Thread spool 71comprises a tapered cylindrical core 72 which is thread wound and thus,takes a generally tapered profile. As shown, thread spool 71 is manuallyplaced over thread spool pin 43 by the user. Because the inner diameterof core 72 is less than outer diameter d1 of positioning mechanism 48 inits initial or original state, inner peripheral surface 72 b of core 72is placed in contact with each of upper link elements 60 of positioningmechanism 48. The outer diameter of positioning mechanism 48 in thiscontext is, as represented by “d1” in FIG. 9A, a diametric dimension ofan imaginary inscribing circle that contacts the three contact sections69 in plan view. The center of the imaginary circle coincides with thecenter or the axial center of spool pin 43.

When the user further presses thread spool 71 downward from the stateshown in FIG. 9B, each of contact sections 69 move toward the axialcenter of thread spool pin 43, meaning that contact sections 69 contractin the radial direction. That is, the downward movement of slider 57,which increases the angle between upper link element 60 and lower linkelement 61, causes each of contact sections 69 to move toward the axialcenter of thread spool pin 43 in equal amounts. The equal contraction ofeach of contact sections 69 allows thread spool 71 to move furtherdownward.

The downward movement of slider 57 compresses compression spring 54.Responsively, the elasticity of compression spring 54 exerts upward biasto urge slider 57 upward. The bias exerted on slider 57 acts as a biasto radially expand or spread contact sections 69 provided at each ofupper link element 60 by way of lower link element 61. Thus, contactsections 69 press inner peripheral surface 73 b of core 72 outward. Asdescribed above, thread spool 71 being pressed by contact sections 69 islocated such that axial center thereof is coincident or concentric withthe axial center of thread spool pin 43 to be attached in place at thelocated position. This is illustrated in FIG. 9C where the diameter ofthe imaginary circle of positioning mechanism 48 is reduced to “d2” andcompression spring 54 is compressed by “a1”.

FIGS. 10A to 10C illustrate a case in which thread spool 81 providedwith core 82 having relatively smaller inner diameter is attached tothread spool pin 43. As apparent from FIG. 10C, the angle defined byupper link element 60 and lower link element 61 is greater as comparedto the example shown in FIGS. 9A to 9C. The diameter of the imaginarycircle defined by positioning mechanism 48 is further reduced to “d3”whereas compression spring 54 is compressed by “a2” which is greater inmagnitude than “a1”.

Of note is that irrespective of downsizing of the diameter of theimaginary circle from “d1”, “d2” to “d3”, the center of the imaginarycircle remains coincident with the center, i.e., the axial center ofthread spool pin 43. Contact sections 69, thus, contract such that eachof the contact sections 69 are equally spaced from the axial center ofthread spool pin 43. Because positioning mechanism 48 is configured tocontract with the inner diameter of cores 72 and 82, that is, the sizeof thread spools 71 and 81, the user is allowed to attach thread spools71 and 81 to thread spool pin 43 such that the center of thread spools71 and 81 are coincident with the axial center of thread spool pin 43without directing extra attention in the difference in size of threadspools 71 and 81.

When the user removes thread spools 71 and 81 from thread spool pin 43,the compressed compression spring 54 is decompressed to its originalstate by its elasticity to place positioning mechanism 48 back to itsoriginal state shown in FIG. 9A or 10A.

According to the above described first exemplary embodiment, contactsections 69 contact inner peripheral surfaces 72 b and 82 b of cores 72and 82 of thread spools 71 and 81 when thread spools 71 and 81 areattached to thread spool pin 43. Contact sections 69 are configured tobe radially displaced by equal amounts responsive to the variation inthe inner diameter of cores 72 and 82. This means that positioningmechanism 48 contracts radially such that the distance between the axialcenter of thread spool pin 43 and each of contact sections 69 are equal.As a result, the axial centers of thread spools 71 and 81 are located atthe same position regardless of their difference in size. Thus, threadspools 71 and 81 can be attached to thread spool 43 at the locationwhere the axial centers of thread spools 71 and 81 coincide with theaxial center of thread spool pin 43. Because positioning mechanism 48 isconfigured to contract with the inner diameter of cores 72 and 82, thatis, the size of thread spools 71 and 81, the user is allowed to attachthread spools 71 and 81 to thread spool pin 43 such that the center ofthread spools 71 and 81 are coincident with the axial center of threadspool pin 43 without directing extra attention in the difference in sizeof thread spools 71 and 81. Stated differently, thread spool standdevice 14 is given greater capacity to accommodate thread spools ofvarious sizes.

Contact sections 69 contact inner peripheral surfaces 72 b and 82 b ofcores 72 and 82 of thread spools 71 and 81 at three locations. Each ofcontact sections 69 moves conjunctively in coordination with one anotherto contract radially in equal distance to allow concerted radialcontraction of positioning mechanism 48. The above described arrangementallows the axial centers of thread spools 71 and 81 to be preciselycoincident with the axial center of the thread spool pin 43.

Contact sections 69 are equally spaced circumferentially from oneanother with an angular interval of 120 degrees. Such arrangement allowsthe axial centers of thread spools 71 and 81 to coincide with the axialcenters of thread spool pin 43 with greater accuracy.

Positioning mechanism 48 is composed of link mechanism 53 andcompression spring 54 and thus, is simple in structure and can beconfigured in low cost.

The elasticity of compression spring 54 biases each of contact sections69 to protrude radially outward by way of respective lower link elements62. As a result, each of contact sections 69 applies pressure on innerperipheral surfaces 72 b and 82 b of cores 72 and 82 of thread spools 71and 81 to retain the coincident positioning of the axial centers ofthread spool 71 and 81 with the axial center of thread spool pin 43.

The three contact sections 69 are each formed on one of the three upperlink elements 60. Thus, once contact sections 69 are placed in contactwith inner peripheral surfaces 72 b and 82 b of cores 72 and 82 ofthread spools 71 and 81 during the attachment of thread spools 71 and 81on thread spool pin 43, contact sections 69 retain the contact until thethread spools 71 and 81 are removed. This again, allows attachment ofthread spools 71 and 81 to thread spool pin 43 such that axial centersof threads spools 71 and 81 are coincident with the axial center ofthread spool pin 43.

Compression spring 54 is employed as an element for imparting elasticityto realize a simple and low cost configuration. The amount ofcompression of compression spring 54 is relatively less when initialcontact is established between contact sections 69 and inner peripheralsurfaces 72 b and 82 b of cores 72 and 82 and thus, contact sections 69only impart weak outward pressure to allow smooth fitting of threadspools 71 and 81 to thread spool pin 43. By the time attachment ofthread spools 71 and 81 are completed, amount of compression ofcompression spring 54 has increased significantly such that contactsections 69 impart a relatively strong outward pressure to reliablylocate thread spools 71 and 81 relative to thread spool pin 43 as wellas reliably securing them to thread spool pin 43.

FIGS. 11A and 11B illustrate a second exemplary embodiment of thepresent disclosure. The portions that are identical to the firstexemplary embodiment are identified with identical reference symbols.The differences from the first exemplary embodiment are describedhereinafter. The second exemplary embodiment provides a feature tochange the positioning of the link base relative to the thread spoolpin.

Between thread spool pin 91 and positioning mechanism 92, positionadjustment mechanism 94 is provided for making adjustments in thepositioning of link mechanism 93 relative to thread spool pin 91. Morespecifically, on the outer peripheral surface of extreme end 91 a sideof thread spool pin 91, male thread 95 is defined which runs in thepredetermined length along thread spool pin 91. Positioning mechanism 92includes link mechanism 93 and compression spring 54. Compression spring54 is fitted over thread spool pin 91 and link mechanism 93 is furtherplaced over thread spool pin 91 such that thread spool pin 91 isinserted through link mechanism 93 and such that link mechanism 93 islocated above compression spring 54.

Link mechanism 93 includes link base 96, three connection links 56, andslider 57. On the inner peripheral surface of the central hole not showndefined through link base 96, female thread 97 is formed that is screwengaged with male thread 95. Position adjustment mechanism 94 isconfigured by male thread 95 of thread spool pin 91 and female thread 97of link base 96. According to the above described configuration, theuser is allowed to make adjustments in the elevation of link base 96being secured to thread spool pin 91 through rotation of link base 96.The rotation of link base 96 causes the rotation of link mechanism 93 inits entirety.

The elevation of each of contact sections 69, that is, the positioningof each of connection link 56 relative to thread spool pin 91 can bechanged by the above described configuration illustrated in FIGS. 11Aand 11B. Because the change in elevation alters the amount ofcompression of compression spring 54, the pressure exerted on the coreof the thread spools by each of contact sections 69 can be adjusted aswell. In an alternative embodiment, the spring constant of compressionspring 54 may be specified such that the elevation of slider 57 is notsignificantly changed with the change in the elevation of link base 96.Further, the angle of bend of each connection link 56 may be changed tomodify the distance between the axial center of thread spool pin 91 toeach of contact sections 69 in addition to the aforementioned adjustmentin the elevation of contact sections 69.

Though the first exemplary embodiment also allows the user to move linkbase 55 up and down by application of force that overwhelms thefrictional force between link base 55 and thread spool pin 43, this isnot readily feasible in the user's point of view. In contrast, thesecond exemplary embodiment allows the user to readily move the linkbase 96 up and down through a simple operation of rotating link base 96around thread spool pin 91. Additionally, compression spring 54 may havevarious ranges of free height and spring constant.

According to the above described second exemplary embodiment, positionadjustment mechanism 94 has been provided for making adjustments in thepositioning of link mechanism 93 and more specifically link base 96relative to thread spool pin 91. Such configuration allows adjustmentsin the elevation of each of contact sections 69 relative to thread spoolpin 91 and in the distance between the axial center of thread spool pin91 and each of contact sections 69 through adjustment in the elevationof link mechanism 93 relative to thread spool pin 91. Such adjustmentsbroaden the capacity of thread spool stand device 14 to accommodatethread spools 71 and 81 having various height and diametric (innerdiameter) dimensions as well as allowing adjustments in the outwardpressure exerted on inner peripheral surfaces 72 b and 82 b of cores 72and 82 of threads spools 71 and 81 by each contact section 69.

Position adjustment mechanism 94 is configured by male thread 95 definedon the outer peripheral surface of thread spool pin 91 and female thread97 defined on link base 96. Adjustments can be made in the positioningof link mechanism 93 relative to thread spool pin 91 by rotating linkbase 96 around thread spool pin 91. Thus, position adjustment mechanism94 can be implemented in a simple and low cost configuration that allowsthe above described adjustments in a simple rotational operation.

The present disclosure is not limited to the foregoing exemplaryembodiments but may be expanded or modified as required.

Link mechanism 53 configured by three connection links 56 beingcircumferentially displaced by 120 degrees maybe replaced by twoconnection links circumferentially displaced by 180 degrees or fourconnection links circumferentially displaced by 90 degrees. Five or moreconnection links may be provided that are circumferentially displaced byconstant interval.

Connection link 56 only requires that the link is configured by at leasttwo segments.

The first exemplary embodiment may be modified such that link base 55 isscrew fastened to thread spool pin 43.

The exemplary embodiments set forth above implement thread spool standdevice 14 that is structurally integral with sewing machine M. However,thread spool stand device 14 may be implemented so as to be structurallyindependent of sewing machine M as shown in FIG. 12. FIG. 12 illustratesthread spool stand device 101 including foot 102, leg 103 extendingupward from foot 102 to hold base 104. On upper surface 104 a of base104, three disc-shaped mount stages 105 to 107 are provided withdisc-shaped thread spool sponges 108 to 110 on top of them. On uppersurface 32 a of base 104, three thread spool pins 111 to 113 extend outof mount stages 105 to 107.

Thread spool pins 111 to 113 each have positioning mechanisms 114 to 116attached on them that are similar in structure to positioning mechanism48 described in the first exemplary embodiment. Provided further onupper surface 32 a is support pillar 117 extending upward to supportthreading member 118 at its upper end. Threading member 118 overhangsthread spool pins 111 to 113 as shown in FIG. 12. FIG. 12 illustratesthe case where thread spool 71 described in the first exemplaryembodiment is attached to thread spool pin 112 and thread spool 81 isattached to thread spool pin 113. The positioning and the bend of eachof connection links relative to thread spool pins 111 to 113 may be madeadjustable as was the case in the second exemplary embodiment.

While various features have been described in conjunction with theexamples outlined above, various alternatives, modifications,variations, and/or improvements of those features and/or examples may bepossible. Accordingly, the examples, as set forth above, are intended tobe illustrative. Various changes may be made without departing from thebroad spirit and scope of the underlying principles.

1. A thread spool stand device including a thread spool base and athread spool pin that has a base end thereof secured to the thread spoolbase and that allows attachment of a thread spool, the thread spoolstand device comprising: a positioning mechanism that determinesposition of attachment of the thread spool relative to the thread spoolpin; wherein the positioning mechanism includes a contact section thatcontacts an inner peripheral surface of a core of the thread spool, thecontact section being radially movable responsive to variation in aninner diameter of the core such that the contact section expandsradially outward or contracts radially inward to be equally spaced froman axial center of the thread spool pin.
 2. The device according toclaim 1, wherein more than one contact section is provided so as tocontact different circumferential portions of the inner peripheralsurface of the core of the thread spool, and wherein the positioningmechanism is configured such that the contact sections are moved inconjunction with one another such that the amount of the expansion andthe contraction are equal.
 3. The device according claim 2, wherein thecontact sections are spaced at equal circumferential interval.
 4. Thedevice according to claim 2, wherein the positioning mechanism furtherincludes: a first support member that is securably disposed at anextreme-end side of the thread spool pin, an elastic member that isprovided on a base-end side of the thread spool pin, a second supportmember that is provided on the base-end side of the thread spool pin soas to be movable in an axial direction of the thread spool pin and thatis placed in consistent contact with the elastic member to beelastically biased by the elastic member; and a plurality of connectionlinks associated with each of the contact sections, wherein each of theconnection links includes: a first link element that has a base-end sidethereof rotatably supported by the first support member and that has thecontact section formed on an extreme-end side thereof, a second linkelement that has a base-end side thereof rotatably supported by thesecond support member; and a connection element that rotatably connectsthe extreme-end sides of the first and the second link elements, whereineach pair of the first and the second link elements define a bend suchthat the contact section protrudes radially outward, the elastic biasexerted on the second support member by the elastic member beingimparted on the contact section byway of the second link element to biasthe contact section to protrude radially outward.
 5. The deviceaccording claim 3, wherein the positioning mechanism further includes: afirst support member that is movably fastened to an extreme-end side ofthe thread spool pin, an elastic member that is provided on a base-endside of the thread spool pin, a second support member that is providedon the base-end side of the thread spool pin so as to be movable in anaxial direction of the thread spool pin and that is placed in consistentcontact with the elastic member to be elastically biased by the elasticmember; and a plurality of connection links associated with each of thecontact sections, wherein each of the connection links includes: a firstlink element that has a base-end side thereof rotatably supported by thefirst support member and that has the contact section formed on anextreme-end side thereof, a second link element that has a base-end sidethereof rotatably supported by the second support member; and aconnection element that rotatably connects the extreme-end sides of thefirst and the second link elements, wherein each pair of the first andthe second link elements define a bend such that the contact sectionprotrudes radially outward, the elastic bias exerted on the secondsupport member by the elastic member being imparted on the contactsection by way of the second link element to bias the contact section toprotrude radially outward.
 6. The device according to claim 4, whereinthe elastic member comprises a compression spring.
 7. The deviceaccording to claim 5, wherein the elastic member comprises a compressionspring.
 8. The device according to claim 4, further comprising aposition adjustment mechanism that allows a position adjustment of thefirst support member being secured to the thread spool pin.
 9. Thedevice according to claim 5, further comprising a position adjustmentmechanism that allows a position adjustment of the first support memberbeing secured to the thread spool pin.
 10. The device according to claim6, further comprising a position adjustment mechanism that allows aposition adjustment of the first support member being secured to thethread spool pin.
 11. The device according to claim 7, furthercomprising a position adjustment mechanism that allows a positionadjustment of the first support member being secured to the thread spoolpin.
 12. The device according claim S, wherein the position adjustmentmechanism includes: a male thread that is formed on an outer peripheralsurface of the thread spool pin, and a female thread that is formed onthe first support member and that is screw engaged with the male thread,wherein the position adjustment of the first support member beingsecured to the thread spool pin is rendered by rotating the firstsupport member around the thread spool pin.
 13. The device accordingclaim 9, wherein the position adjustment mechanism includes: a malethread that is formed on an outer peripheral surface of the thread spoolpin, and a female thread that is formed on the first support member andthat is screw engaged with the male thread, wherein the positionadjustment of the first support member being secured to the thread spoolpin is rendered by rotating the first support member around the threadspool pin.
 14. The device according claim 10, wherein the positionadjustment mechanism includes: a male thread that is formed on an outerperipheral surface of the thread spool pin, and a female thread that isformed on the first support member and that is screw engaged with themale thread, wherein the position adjustment of the first support memberbeing secured to the thread spool pin is rendered by rotating the firstsupport member around the thread spool pin.
 15. The device accordingclaim 11, wherein the position adjustment mechanism includes: a malethread that is formed on an outer peripheral surface of the thread spoolpin, and a female thread that is formed on the first support member andthat is screw engaged with the male thread, wherein the positionadjustment of the first support member being secured to the thread spoolpin is rendered by rotating the first support member around the threadspool pin.
 16. A sewing machine provided with a thread spool standdevice including a thread spool base and a thread spool pin that has abase end thereof secured to the thread spool base and that allowsattachment of a thread spool, sewing machine comprising: a positioningmechanism that determines position of attachment of the thread spoolrelative to the thread spool pin; wherein the positioning mechanismincludes a contact section that contacts an inner peripheral surface ofa core of the thread spool, the contact section being radially movableresponsive to variation in an inner diameter of the core such that thecontact section expands radially outward or contracts radially inward tobe equally spaced from an axial center of the thread spool pin.